Graphite has excellent industrial properties such as its lubricating ability, its conductivity, its heat resistance, and its chemical resistance, and it is used in a wide range of fields such as the fields of semiconductors, nuclear energy, aviation, and machinery. Graphite is produced by, for example, heating carbon powder to a high temperature (for example, 2000 to 3000° C.) in a graphitization furnace.
Technology for this type of graphitization furnace has been disclosed in which a carbon powder injection port is provided in a top portion of the graphitization furnace, a graphite powder recovery port is provided in a bottom portion of the graphitization furnace, and a plurality of sets of electrodes are provided on either side in a horizontal direction and facing an area between the injection port and the recovery port through which the carbon powder passes. Each set of electrodes is then energized in sequence at mutually offset timings (see, for example, Patent document 1). In addition, technology has also been disclosed in which a case containing carbon powder is inserted between an upper electrode and a lower electrode, and the carbon powder is heated by energization (see, for example, Patent document 2).